Behavioral Treatments for Alcohol Use Disorder and Post-Traumatic Stress Disorder.

Alcohol use disorder (AUD) and post-traumatic stress disorder (PTSD) are highly prevalent and debilitating psychiatric conditions that commonly co-occur. Individuals with comorbid AUD and PTSD incur heightened risk for other psychiatric problems (e.g., depression and anxiety), impaired vocational and social functioning, and poor treatment outcomes. This review describes evidence-supported behavioral interventions for treating AUD alone, PTSD alone, and comorbid AUD and PTSD. Evidence-based behavioral interventions for AUD include relapse prevention, contingency management, motivational enhancement, couples therapy, 12-step facilitation, community reinforcement, and mindfulness. Evidence-based PTSD interventions include prolonged exposure therapy, cognitive processing therapy, eye movement desensitization and reprocessing, psychotherapy incorporating narrative exposure, and present-centered therapy. The differing theories behind sequential versus integrated treatment of comorbid AUD and PTSD are presented, as is evidence supporting the use of integrated treatment models. Future research on this complex, dual-diagnosis population is necessary to improve understanding of how individual characteristics, such as gender and treatment goals, affect treatment outcome.

indicate that efective treatments are scant, and there is substantial room for improvement. [4][5][6][7][8][9] Furthermore, individuals with co-occurring AUD and PTSD sufer a more complicated course of treatment and less favorable treatment outcomes, when compared with individuals who have either disorder alone. [15][16][17][18][19] Terefore, identifying efective interventions to treat co-occurring AUD and PTSD is a national public health priority. Tis review describes evidence-supported interventions targeting AUD and PTSD individually and in the context of co-occurrence.

Behavioral Treatments for AUD
Behavioral interventions are a primary component of the treatment of AUD and can be used as freestanding treatments or as part of a more comprehensive treatment plan that includes pharmacotherapies. Behavioral interventions for AUD include providing psychoeducation on addiction, teaching healthy coping skills, improving interpersonal functioning, bolstering social support, increasing motivation and readiness to change, and fostering treatment compliance.
Cognitive behavioral therapies (CBTs) are some of the most commonly used and empirically supported behavioral treatments for AUD. 20,21 Over the past 30 years, numerous meta-analyses and systematic reviews have demonstrated that CBT is an efective treatment for AUD. 20,[22][23][24][25] For substance use disorders, small but statistically signifcant treatment efects have been observed for various types of CBT. 24 CBT interventions typically are designed as short-term, highly focused treatments that can be implemented in a wide range of clinical settings. Tese interventions are fexible and can be applied in individual or group therapy formats. CBTs for AUD focus on the identifcation and modifcation of maladaptive cognitions and behaviors that contribute to alcohol misuse. 21 Behavioral treatments for people with AUD also target motivation for change and improvement of specifc skills to reduce the risk for relapse.
Although most behavioral interventions are designed as short-term treatments (e.g., 8 to 20 sessions), many people struggling with AUD require long-term treatment. Depending on the severity of the AUD, history of treatment attempts, family history, and other risk factors, some individuals will remain in various stages of treatment for years to maintain sobriety. Furthermore, many individuals with AUD will complete several rounds of treatment and engage in several diferent types of treatment simultaneously (e.g., CBT and 12-step engagement). In this section, we briefy review several empirically supported behavioral interventions for AUD. (Higgins and colleagues provide more information on behavioral interventions for substance use disorders. 26 )

Relapse prevention
For the past 30 years, relapse prevention 27 has been one of the prevailing empirically supported CBTs for AUD. 20 Relapse prevention is designed to help people with AUD identify high-risk situations for relapse (e.g., negative emotional states and alcohol-related cues) and develop efective coping strategies. 21,28 Tis intervention encourages behavioral strategies such as avoiding or minimizing exposure to cues that trigger cravings, engaging in pleasant activities, and attending self-help groups. In addition, individuals receiving this treatment learn to recognize warning signs that typically precede a relapse and create a relapse management plan (i.e., an emergency plan for what to do if a relapse occurs). Relapse prevention also focuses on strategies for challenging relapse-related cognitions (e.g., "A few drinks won't hurt"). In a review of 24 randomized controlled trials, relapse prevention was associated with reductions in relapse severity and with sustained and durable efects. 29 Evidence from the review suggests that relapse prevention is most efective for those who have negative afect, more severe substance use disorder, and greater defcits in coping skills.

Contingency management
Contingency management is a behavioral therapy that employs the basic behavioral principles of positive and negative reinforcement to promote the initiation and maintenance of abstinence or other positive behavior changes. 30,31 Te most thoroughly researched form of contingency management involves monetary-based reinforcement, in which money or vouchers can be earned and exchanged for prizes, contingent on meeting therapeutic goals. 32 Often, the primary goal is abstinence, but other goals may include therapy attendance, prosocial behaviors, or compliance with medications. 21,26 Contingency management is designed to help promote initial abstinence of substance use. Tis intervention can be particularly helpful when the individuals receiving treatment have little or no internal motivation, or if they lack natural reinforcers, such as family relationships. 26,33 Numerous studies show that contingency management can increase abstinence, clinic attendance, and medication compliance. 32,[34][35][36][37]

Motivational enhancement
Motivational enhancement therapy is an intervention designed to enhance internal motivation for change and engagement in the change process. 38,39 Tis therapy stemmed from the recognition that many individuals with AUD are ambivalent about changing their behavior, unmotivated, or not ready for change. Motivational enhancement therapy can be used as a stand-alone treatment or in combination with other behavioral interventions. 21,40 Based on the principles of motivational interviewing, 41 this therapeutic technique is collaborative, empathetic, and nonconfrontational. It helps individuals with AUD resolve ambivalence about quitting or reducing their alcohol intake, increase their awareness of the negative consequences of drinking alcohol and the positive benefts of abstinence, and resolve values discrepancies (e.g., valuing physical health is incompatible with alcohol misuse). Motivational enhancement therapy has been shown to be particularly efective for individuals who have AUD, for those who use nicotine, and for participants who have substance use disorder and a problem with anger. 25,40,[42][43][44][45]

Couples therapy
Alcohol behavioral couple therapy 46 and behavioral couples therapy for alcoholism and drug abuse 47 are manual-guided (also known as manualized) treatments for AUD that incorporate participation of a signifcant other or romantic partner. Most efective AUD treatments target individuals, but these two therapies also target relationship functioning, which is an important mechanism in the etiology, course, and treatment of AUD. 8,9 Both of these therapies involve 12 weekly, 60-to 90-minute sessions that focus on psychoeducation and cognitive behavioral interventions. Te interventions target relationship skills and skills related to reducing AUD severity. Alcohol behavioral couple therapy uses motivational interviewing techniques and focuses on harm reduction, and behavioral couples therapy for alcoholism and drug abuse emphasizes attaining and maintaining abstinence.

Twelve-step facilitation
Twelve-step facilitation is a manual-guided intervention for AUD that is based on the 12 steps of Alcoholics Anonymous. 48 Twelve-step facilitation is designed to help with early recovery and to help people engage with a local Alcoholics Anonymous or other 12-step therapy group in the community. 21 Tis therapy focuses on acceptance of addiction as a chronic and progressive illness, acceptance of the loss of control over drinking, surrendering to a higher power, lifelong abstinence from alcohol, and fellowship through a group. Participants are encouraged to obtain a sponsor who will serve as a source of practical advice and support during recovery. Data from the National Institute on Alcohol Abuse and Alcoholism project Matching Alcoholism Treatment to Client Heterogeneity (Project MATCH) found that individuals who received 12-step facilitation, compared to cognitive behavioral or motivational enhancement therapies, were signifcantly more likely to be abstinent at follow-up visits during the 3 years after treatment. 25 In addition, in the Project MATCH study, 12-step facilitation was found to be particularly helpful for participants whose social networks included other people who had substance use disorders.

Community reinforcement
Te community reinforcement approach is a CBT designed to enhance social, recreational, and vocational skills. 21 Participants learn confict resolution skills, ways to foster healthy relationships, and how to develop a new social network. 26 Tis approach is diferent from other CBT interventions in that it targets a person's reinforcers (e.g., family, friends, work, and hobbies) and helps reconnect that person with these sources of reinforcement. 21 Community reinforcement is often combined with contingency management approaches to deliver external reinforcers (e.g., money) during the initial treatment period, to be followed by more natural sources of reinforcement (e.g., family and recreation) in the later stages of treatment. 26 Treatment with disulfram is ofered as part of the community reinforcement approach to help decrease alcohol use. In addition to increasing abstinence, this approach has been shown to reduce the time spent drinking and the time spent being unemployed, away from family, and institutionalized. 26

Mindfulness
More recently, several mindfulness-based interventions have been developed for the treatment of substance use disorders. In general, mindfulness practices seek to redirect attention to the present moment and strengthen the development of nonattached acceptance of both pleasant and aversive experiences. One such intervention, mindfulnessbased relapse prevention, builds on traditional relapse prevention. 49 Tis intervention typically is delivered in an 8-week group format and includes psychoeducation regarding mindfulness and relapse, breath-focused awareness, body-scan exercise, and yoga mindfulness exercise. In one study, a mindfulness-based relapse prevention intervention resulted in reductions in heavy drinking, when compared with standard relapse prevention. 50 Te same researchers reported that the mindfulness-based approach may have yielded more enduring efects than standard relapse prevention, as evidenced by a signifcantly lower probability of heavy drinking at a 12-month follow-up for the participants who received the mindfulness-based intervention. However, a recent meta-analysis of nine randomized controlled trials found no diferences in relapse between mindfulness-based relapse prevention and comparable interventions, such as relapse prevention. 51 Another intervention, mindfulness-oriented recovery enhancement, is a group intervention delivered over 8 to 10 sessions. 52 Tis intervention includes mindfulness training, cognitive restructuring, and savoring strategies designed to enhance positive emotions and salience of naturally occurring rewards. Less research has been conducted using this intervention, but one study found that mindfulness-oriented recovery enhancement resulted in reduced cravings and negative afect and improved positive afect. 53

Behavioral Treatments for PTSD
Behavioral intervention is considered a frst-line approach in the treatment of PTSD. Several empirically supported behavioral interventions have been disseminated across populations and treatment settings. As with treatments for AUD, various treatment modalities for PTSD have been studied. Comprehensive analysis of the literature on this topic is challenging because of the diversity of inclusion and exclusion criteria of participants, the heterogeneous nature of PTSD symptoms, high treatment dropout rates, and symptoms that persist after treatment. [54][55][56][57][58] Meta-analytic reviews of these treatments indicate that prolonged exposure therapy, cognitive processing therapy, and eye movement desensitization and reprocessing are among the most frequently and rigorously examined treatment options. In randomized clinical trials, these treatments all have similar levels of efectiveness. [59][60][61][62] CBTs for PTSD are based on prevailing empirically supported etiological theories that suggest PTSD results from learned and exacerbated fear reactivity and disrupted cognitive and afective responses to trauma exposure. 63 Targeting these processes in cognitive behavioral interventions typically results in substantial improvement in PTSD symptom severity 60,64 and in various domains of functioning, when compared with unstructured interventions or usual treatment conditions. [65][66][67] Treatment guidelines indicate that exposure-based psychotherapies have sufcient empirical evidence to be deemed efective PTSD treatments. [60][61][62][63][64][65][66][67][68] Tese and other emerging therapies are described in this section.

Prolonged exposure
Prolonged exposure is a manual-guided CBT consisting of 10 weekly, 60-to 90-minute individual therapy sessions. 54 Te central therapeutic component of prolonged exposure is based on Pavlovian learning theory. Te treatment involves repeatedly presenting a conditioned stimulus (e.g., a trauma reminder) in the absence of an unconditioned stimulus (e.g., the traumatic event). Tis is accomplished through imaginal exposure during therapy sessions and through in vivo exposure in the environment. On average, prolonged exposure demonstrates robust symptom severity improvement. 69

Cognitive processing
Another manual-guided cognitive behavioral modality that has received strong empirical support for the treatment of PTSD is cognitive processing therapy. 70 Cognitive processing therapy consists of 12 weekly, 60-minute individual sessions. Tis therapy involves creating and discussing written narratives describing the thoughts and emotions related to the traumatic event. Participants receive homework assignments designed to identify and challenge the maladaptive thought patterns that are central to the development and maintenance of PTSD symptomatology. A modifed, group therapy version of cognitive processing therapy was designed and tested, with promising results. 65 Evidence also supports the efectiveness of cognitiveonly cognitive processing therapy, 71 which includes psychoeducation about PTSD, cognitive skillbuilding, and learning cognitive restructuring skills. Te cognitive-only therapy does not employ written narratives, and the most recent treatment manual recommends the cognitive-only therapy as the frstline version, with written narratives as an optional modifcation. 72

Eye movement desensitization and reprocessing
For the treatment of PTSD, eye movement desensitization and reprocessing has received empirical support 73 and is one of the therapies that has received endorsement in recent U.S. Department of Veterans Afairs and U.S. Department of Defense treatment guidelines. Eye movement desensitization and reprocessing is one of the three most-studied treatments for PTSD. 59 Tis therapy incorporates a variety of techniques, including prolonged exposure and cognitive restructuring, but it difers in that it applies these techniques in conjunction with guided eye movement exercises.

Narrative exposure
Narrative exposure therapy is a manual-guided psychotherapy developed to treat PTSD among individuals seeking asylum from political or organized violence. 74 In this technique, which also includes psychoeducation about PTSD, participants narrate their relevant developmental memories in chronological order and narrate details of their trauma exposures as they were experienced over time. Typically, the sessions are 60 to 120 minutes, approximately once a week for 4 to 10 weeks.

Present-centered therapy
Present-centered therapy is a time-limited intervention that includes a psychoeducation component, skill development to manage daily stressors and challenges, and homework to solidify the new skills developed in sessions. 75,76 Tis therapy has demonstrated efcacy in a variety of populations and is commonly used in randomized controlled trials as a comparator for new or adapted PTSD treatments. 77

Cognitive behavioral conjoint therapy
Cognitive behavioral conjoint therapy for PTSD is a manual-guided, 15-session CBT. 78 Tis intervention is designed to improve PTSD symptoms and relationships at the same time. Research in this area is critical, as dyadic distress and dysfunction are saliently associated with poor individual PTSD treatment outcomes. Cognitive behavioral conjoint therapy involves psychoeducation on PTSD and relationships, learning communication skills to address avoidance related to PTSD and relationship problems, and challenging trauma-related beliefs.

Other interventions
Additional interventions that integrate cognitive behavioral and other therapeutic approaches include emotion-focused therapy 79 and brief eclectic psychotherapy. 80 Te empirical literature on these approaches is limited, but the research demonstrates promising fndings.

Behavioral Treatments for Comorbid AUD and PTSD
Problems with alcohol use have been included in the Diagnostic and Statistical Manual of Mental Disorders since its original 1952 edition, but PTSD was not introduced as a psychiatric diagnosis until the third edition in 1980. 81 Since 1980, behavioral treatments for comorbid AUD and PTSD often have been conducted sequentially, with alcohol-frst treatments being more prevalent than PTSD-frst treatments. Teoretically, achievement of abstinence facilitates development of cognitive skills such as impulse control and emotion regulation. Tese skills are subsequently useful in trauma-focused therapies, and they help minimize the risk of alcohol use as a means of avoiding trauma processing. However, individuals with comorbid AUD and PTSD often request integrated treatment or are unwilling to stop drinking alcohol. Opponents of PTSD-frst and integrated treatments voice concern that AUD symptoms will worsen if skills promoting abstinence are not well-developed frst, and that PTSD symptomatology will also worsen overall. [82][83][84] Irrespective of the theoretical debate, epidemiologic evidence suggests that integrated treatments are not yet widely used in substance use disorder treatment centers. 8,84 Data from the Substance Abuse and Mental Health Services Administration (SAMHSA) National Survey of Substance Abuse Treatment Services (N-SSATS): 2016 indicate that although 77% of the responding facilities at least "sometimes" ofered some form of trauma-related counseling, only 38% reported "always or often" using this approach. 85 Tis percentage has improved slightly since SAMHSA's 2009 N-SSATS report, when 67% of respondents reported "sometimes, often, or always" ofering trauma-focused treatment. In 2012, Capezza and Najavits noted that additional studies about "the content of trauma counseling currently ofered by facilities" and "whether the treatment is informed by the evidence" would be useful. 86 To better understand why integrated treatments are not used as often as sequential treatments, Gielen and colleagues conducted a qualitative study of health care provider views on treating PTSD in patients with co-occurring substance use disorder. 87 Te researchers reported that health care providers underestimate the prevalence of the comorbid conditions. Given that only 50% of substance use disorder treatment centers endorse providing a comprehensive mental health assessment, it is likely that PTSD is not systematically identifed in many initial diagnostic assessments. Only 66% of substance use disorder treatment centers report ofering any form of mental health treatment not related to substance misuse. 85 Gielen and colleagues noted that health care providers frequently appreciate that comorbid AUD and PTSD are associated with more severe symptomatology and worse treatment outcomes. 87 Tey also found that health care providers frequently expressed the belief that integrated treatment of AUD and PTSD would worsen cravings and reduce AUD treatment retention and efcacy. When studying the efectiveness of integrated treatments, researchers consistently use standardized therapies. However, at community substance abuse treatment centers, these therapies may not be routinely available because providers may not be trained in these approaches. Also, in some settings, providers may not be familiar with validated, standardized methods of PTSD screening. SAMHSA's 2016 N-SSATS report did not comment on staf training levels at substance abuse treatment centers. Identifying methods to address the need for standardized treatments is an important area for future research.
Despite health care provider concerns about implementing integrated behavioral treatments for comorbid AUD and PTSD, a growing evidence base indicates that integrated treatments are safe, feasible, well-tolerated, and efective. 9,[88][89][90][91][92][93][94] In a recent review, Simpson and colleagues evaluated 24 randomized clinical trials (N = 2,294) from studies of behavioral treatments for comorbid PTSD and substance use disorder. 9 Te trials were grouped into three categories: (1) exposure-based treatments, (2) coping-based strategies, and (3) addiction-focused interventions. No signifcant diferences in treatment retention were found across the three groups.
However, it is important to note that for the 24 trials, treatment retention measures varied widely. 9 For example, one trial measured treatment retention as attendance at 12 out of 12 sessions, but another trial calculated the average number of sessions attended and determined that treatment was completed if participants fnished at least 6 out of 25 sessions. Another trial evaluated retention based on participant provision of a urine sample at the end of 12 weeks.
Accounting for these measurement diferences, participant retention for trauma-focused studies was approximately 51%. 9 Retention was about 50% for nontrauma-focused studies and about 44% for studies that focused on substance use disorders. Te trials' control conditions had more retention than the experimental conditions, with 72% participant retention for trauma-focused studies, 53% for nontrauma-focused studies, and 31% for studies that focused on substance use disorders.
Te analysis conducted by Simpson and colleagues included only a small number of studies, and more research on this topic is needed, as treatment retention among individuals with co-occurring PTSD and substance use disorder has signifcant room for improvement. 9 Overall, the data indicate that trauma-focused treatments are an efective approach for reducing PTSD severity. Tus, integrated trauma-focused treatments are recommended for individuals with comorbid AUD and PTSD. 7,9 Furthermore, many people report that they prefer integrated models of treatment to sequential models. 95 Integrated treatments are linked with the self-medication hypothesis, which suggests that substances are often used as a means to manage distress associated with PTSD symptoms. Tus, integrated treatments for AUD and PTSD comorbidity have the advantages of acknowledging the interplay between AUD and PTSD symptoms and of targeting both conditions simultaneously with one health care provider and one treatment episode. Te integrated model is further supported by studies indicating that PTSD symptom improvement infuences subsequent AUD symptom improvement more than AUD symptom changes infuence subsequent PTSD symptoms. 18,96

Integrated Behavioral Treatments
Treatment of comorbid AUD and PTSD presents substantial challenges to providers across disciplines and treatment settings. Individuals who have both AUD and PTSD demonstrate high-risk behaviors more often than those who have only one diagnosis; consequently, they require high levels of monitoring and intervention. 84,97 Tus, developing efective integrated behavioral interventions to treat comorbid AUD and PTSD is a public health priority. Trials of integrated treatments demonstrate that substance use and PTSD severity decrease with the use of traumafocused interventions, and these efects are largely maintained at 3-, 6-, and 9-month follow-ups. 98-100

Seeking safety
Te seeking safety approach, a 25-session CBT focused on developing strategies to establish and maintain safety, is one of the most widely studied integrated treatments. 101 Originally, seeking safety was designed as a group intervention, but it has also been studied as an individual format. Te intervention has been shown to reduce symptoms of AUD and PTSD for a range of populations (e.g., women, men, veterans, and people who are incarcerated). [102][103][104][105] Some studies showed that participants who received the seeking safety approach had better substance use outcomes than those who received treatment as usual. However, other studies found no treatment group diferences for substance use or PTSD severity. 106 Te seeking safety approach, like most of the integrated treatments, does not include discussions of trauma memories or events, primarily because providers have concerns about using exposurebased practices in a group format and with people who have comorbid substance use disorder and PTSD. 107 However, given the abundance of literature documenting the efcacy of prolonged exposure in the treatment of PTSD, development of exposure-based interventions for the treatment of comorbid AUD and PTSD has increased. A number of studies now demonstrate the safety and feasibility of employing exposure-based interventions among individuals who have PTSD and comorbid substance use disorders. 9,90,91,93,108

Concurrent treatment of PTSD and substance use disorders using prolonged exposure (COPE)
A manual-guided, integrated therapy that has demonstrated efcacy in treating comorbid AUD and PTSD is concurrent treatment of PTSD and substance use disorders using prolonged exposure. 109 Tis therapy is a 12-session, individual intervention that synthesizes empirically validated, cognitive behavioral treatment for AUD with prolonged exposure therapy for PTSD. 110 Several randomized controlled trials conducted in the United States and internationally demonstrate that this treatment signifcantly reduces AUD and PTSD severity. 96,100,111

Other treatments
Another cognitive behavioral approach to integrated treatment for comorbid AUD and PTSD is integrated cognitive behavioral therapy, which is a manual-guided intervention with preliminary, but growing, empirical support. 99,112 Tis treatment consists of 8 to 12 weekly sessions for the individual and focuses on psychoeducation, mindful relaxation, coping skills, and cognitive fexibility.
Other interventions include the trauma recovery and empowerment model, which was designed for women, and a version of the same therapy designed for men. 113 Tese interventions are group-based, focus on recovery skills, and have demonstrated reductions in substance use. 114 Also, couple treatment for AUD and PTSD, a 15-session couple therapy adapted from Monson and Fredman's cognitive behavioral conjoint therapy for PTSD, 78 has promising preliminary empirical support. 115 Other treatments with limited or preliminary empirical support are "transcend," a 12-week partial hospitalization program that integrates cognitive behavioral and other theoretical approaches; 116 the addictions and trauma recovery integrated model, an individual approach that focuses on reconstructing trauma memories; 117 and trauma adaptive recovery group education and therapy, a group intervention designed to enhance emotion regulation. 118 (See Table 1 for brief descriptions of the integrated treatments discussed in this section.)

Future Research
Over the past few decades, important advances have been made in behavioral treatments for comorbid AUD and PTSD. Te most notable area of progress is the development of trauma-informed, manual-guided, integrated, cognitive behavioral treatments that concurrently address symptoms of both conditions. Before these developments, sequential treatment was the only form of behavioral intervention employed. Now, individuals with comorbid AUD and PTSD, as well as their health For future research, it will be important to continue to advance and optimize integrated treatments and to address which individuals are ideal candidates for integrated therapies. Despite the established efcacy of integrated treatments and reported preferences for this type of therapy, treatment retention and dropout rates remain an important area of concern in this dual-diagnosis population. 99,100 Further study that directly compares sequential and integrated treatment outcomes is necessary. One ongoing study addresses this gap in the literature by assessing whether retention rates between sequential and integrated treatments difer. 119 Studies that compare other outcomes related to treatment retention and symptom improvement, such as sleep, mood symptoms, somatic medical conditions, and safety profles (including violence and suicidality), would also be helpful. Te literature currently lacks studies that examine the association between premorbid functioning and the ability to engage in manual-guided, evidence-supported therapies. Also needed is examination of how adding PTSD-focused treatment to AUD treatment will be feasible in terms of treatment costs, training requirements, and staf workload. Te overlap of AUD with other substance use disorders is highly prevalent. Studies examining outcomes of integrated treatments among people with comorbid AUD and PTSD, when compared with people who have PTSD and substance use disorder involving multiple substances, is necessary to identify and target specifc alcohol-related treatment needs. Finally, given the heterogeneous nature of AUD 120 and the complex etiology, course, and treatment of both AUD and PTSD, studies that examine commonalities underlying efective behavioral treatments are essential.
Gender is another important consideration in the development of efective treatments for comorbid AUD and PTSD. Critical psychosocial and neurobiological diferences between men and women have been demonstrated through research on the connection between stress (e.g., exposure to sexual trauma) and substance use disorder in the context of complex comorbidities. 121,122 Also, gender may be a factor in the utilization of treatment for these conditions. 123 Finally, individual preference is a critical consideration when matching people with treatment modalities. Emerging literature suggests that many people who have both PTSD and substance use disorder symptoms perceive a strong link between them, and they prefer integrated versus sequential treatment. 124,125 Also, individuals receiving treatment might have a goal to reduce substance use rather than attain or maintain abstinence. 126 Investigations that consider these individual and contextual factors are necessary to efectively match treatment approaches with individual needs and to maximize treatment development research for comorbid PTSD and AUD.